FLINT HILLS GEOLOGY
MAPPING EXERCISES

GO 547/ES 747

James S. Aber
Earth Science Department
Emporia State University
Emporia, Kansas 66801

Table of Contents
Introduction
Lake Kahola vicinity
Cattle pens vicinity
Ross Natural History Reservation

Introduction

Three mapping exercises will be undertaken by students during the first and second weeks of June. Each exercise involves field observations, construction of a map of surficial geology, and a report of methods and findings--see
geologic maps. The exercise sites range in area from about 1½ square miles to 12 square miles. Each of the sites is described below. Detailed topographic maps, airphotos, and other information will be supplied for students during field mapping of these sites.

Lake Kahola vicinity

Lake Kahola is a small water-supply and recreational lake in northeastern Chase and southeastern Morris counties. The lake is contained behind a man-made dam on Kahola Creek. The surrounding hills are underlain by lower Permian bedrock, ranging from the Eskridge Shale upward to the Florence Limestone. The Crouse Limestone forms a prominent stoneline on the hillsides along the eastern and southern sides of the basin. The Crouse was quarried for materials used in dam construction in the 1930s.

Within Kahola Creek valley, alluvial deposits are found on terraces beside the lake, as well as on the floodplain upstream and downstream from the lake. Numerous springs exist along the southern side of the lake--some are perennial, others are intermittent. Lake Kahola was constructed in this location because the springs provide a reliable water source during droughts.

Landsat TM image of Kahola-Ross region, east-central Kansas. Agricultural landuse is predominent in larger valleys, and the uplands are mostly prairie grassland. False-color composite made of TM bands 2, 5 and 7 color-coded as blue, green and red; image date 09/11/97.

More views of Lake Kahola vicinity.

The field mapping area encompasses six sections (6 square miles) that include and surround the lake. Public access is available around the whole of the lake perimeter and on county roads. However, students should not cross fences onto private ranch land.

Cattle pens vicinity

The cattle pens exit from the Kansas Turnpike (I-35) leads to a county road that winds through open range of the tallgrass prairie. The terrain displays the classic erosional topography of the Flint Hills in which limestone units form flat-topped hills and steep benches on hillsides. Shale units are eroded into more rounded hills and gentler hill slopes. The lower Permian bedrock ranges from the Burr Limestone upward through the Florence Limestone. Small areas of alluvial deposits exist within and along the larger stream valleys.

Landsat TM image of cattle pens region, east-central Kansas. The cattle pens are located on the divide between the Cottonwood drainage basin (left) and Verdigris basin (right). The most distinctive drainage feature is the right-angle valley bend in the center of the scene. False-color composite made of TM bands 2, 5 and 7 color-coded as blue, green and red; image date 09/11/97.

The exercise region includes 12 sections (12 square miles) of open prairie, part of the Nation Ranch. We have permission to walk throughout the mapping area in order to make geological observations and measurements. The portion north of the turnpike is part of the antelope restoration area, although it's not likely that students will see antelope at this time of year. Early June is a great time to view prairie wildflowers, but cattle pastures are infested with chiggers, so bring insect repellent!

Ross Natural History Reservation

Ross Natural History Reservation is located at the extreme eastern margin of the Flint Hills, marked by the Neva Limestone. The lower Permian bedrock geology includes, from the top down: Cottonwood Limestone, Eskridge Shale, Neva Limestone, and underlying units. Small areas of alluvial sediment are found along a stream that drains the northeastern portion of the reservation. Several small man-made ponds are present along with a perennial spring.

Digital orthophotograph of Ross Natural History Reservation, east-central Kansas. The Cottonwood Limestone forms a prominent stone line in the western portion of this scene (note quarry); the Neva Limestone displays a less noticable stone line in the eastern portion. The road along the western margin marks the Chase-Lyon county boundary.

More views of Ross vicinity.

The exercise mapping area is relatively small--only about 1½ square miles, and the bedrock stratigraphy is fairly simple. Our goal is to determine the geological conditions that give rise to the perennial spring, which is located in an unusual position. Students can walk throughout the mapping area to make geological observations and measurements, but sample collection is prohibited. As part of the Ross exercise, students will construct summary rose diagrams of all joint measurements taken at all mapping sites in the Flint Hills.

Return to Flint Hills geology.
J.S. Aber © 2002.